CH-47: Offloading Innovation
A request for off-loading equipment last summer by a member of the Army’s Rapid Equipping Force operating in Southwest Asia has resulted in new equipment in-theater. Working with packaging and materiel experts as well as CH-47 crew members to shape the requirements and design concepts, the U.S. Army Soldier Systems Center in Natick, Mass. developed a field-expedient fix that met key criteria by using commercially-available conveyor rollers along with wooden ramp extensions, complementing existing off-load extensions. It was developed within 90 days, and 120 roller systems were sent to Southwest Asia after the evaluation. Another order of 60 is on the way. The system is an alternative to the Helicopter Internal Cargo Handling System (HICHS), which has some reported field drawbacks in certain situations and is also reported to have had availability issues.
From Soldier Systems Center (Nantick), The Warrior, January-February 2005:
Chinook cargo ramp hastens delivery, leaves passenger room
Bad enough spending time and effort muscling a loaded pallet of supplies off a CH-47 helicopter, cargo often got banged up when it tripped and tumbled out the door.
Help is on the way. A request for off-loading equipment last summer by a member of the Army’s Rapid Equipping Force operating in Southwest Asia eventually led to the Aerial Delivery and Engineering Support Team at the U.S. Army Soldier Systems Center in Natick, Mass., developing a field-expedient fix within 90 days.
Two rows of commercially-available rollers enable Soldiers to quickly and easily push out cargo pallets from a CH-47 helicopter.
Commercially-available conveyor rollers along with wooden ramp extensions, complementing existing off-load extensions, provide a quick, easy and inexpensive way to move out cargo without sacrificing troop transit, said Bob Pitts, an equipment specialist and project officer for the CH-47 Rapid Off-Load.
“Everybody down there said ‘I wish I would have had this when I was there,'” Pitts said about the pilots, crew chiefs and flight engineers with combat experience in Afghanistan and Iraq taking part in an evaluation at Fort Campbell, Ky.
After the evaluation, 120 roller systems were sent to Southwest Asia, with another order of 60 on the way.
Since the 1960s, the CH-47 Chinook helicopter has delivered troops and equipment to almost any type of terrain. They have been flown for airborne missions, casualty evacuation, downed aircraft recovery, disaster relief, and search and rescue missions during war and peace, according to Pitts.
He said flying cargo externally with a sling load is an option with the CH-47, but crews don’t prefer it because extra drag reduces speed and increases fuel consumption, and because of the type of flying they do.
Kick pallets without the roller system are off-loaded from a CH-47 helicopter in Southwest Asia.
To keep it inside, the Helicopter Internal Cargo Handling System (HICHS) has been available for more than a decade. The system provides low-friction loading and unloading conveyor ramps along with conveyors for moving cargo within the aircraft.
“It’s a good system for the loads that it is designed for, but it has drawbacks,” Pitts said. “HICHS was not in there most of the time. Once configured, you want to leave it that way because it’s difficult and time-consuming to install. The 463L pallet is too big to move around, and it doesn’t allow any space to carry troops.”
It also has limited availability, with the HICHS allocated to one-fourth of the Chinook fleet. Operations in Afghanistan and Iraq renewed interest in internal cargo delivery and spurred field improvisation with locally-built “kick pallets,” according to Pitts, which still allow room for passengers.
Kick pallets are double the length of the industry-standard warehouse pallet but half the size of the costlier 463L pallet. They often became snagged inside the helicopter and sometimes had to be pushed out as the helicopter took off, he said. Increased time in landing zones increased risk of enemy fire and tipped over pallets resulted in damaged supplies.
Rollers are strapped onto the cabin floor and leave enough room for passengers along the sides.
On the other hand, kick pallets placed in the center freed 20 passenger spaces on each side, keeping troops and their supplies together.
The Aerial Delivery and Engineering Support Team worked with packaging and materiel experts as well as CH-47 crew members to shape the requirements and design concepts leading to a system working with both kick pallets and warehouse pallets.
It met the criteria of allowing up to four pallets to be unloaded within 10 minutes, clearing the ramp area by 30 feet, giving enough pallet clearance without having to taxi the helicopter forward and working on any type of terrain. Chinooks with the new system can be configured to carry all cargo or a combination of passengers and cargo.
“We did nothing that modifies the aircraft at all. It’s compatible with the armor protection,” Pitts said. “We still get the same volumetric capacity as before without losing troop carrying capacity using rollers and pallets you can get anywhere.”
The rollers, which could be wide or the thin skate-wheel variety, are ladder-shaped and strap down onto the cabin floor. When it’s time to exit, the rollers are extended into place along with the wooden wedges slid underneath to support the weight as pallets move down the line.
Wooden wedges slide underneath to support the weight of the pallets.
Chances of a spilled pallet are lowered, and extra wood planks underneath the rollers help reduce friction when a pallet is pushed or pulled along the rollers.
Pitts said changes ahead might include adding a smooth surface underneath the pallets for extra stability on the rollers and developing a roller system based on the warehouse pallet.
A roller system using warehouse or kick pallets could also be added to light tactical vehicles, such as the Humvee, he said. With “stick on” cardboard honeycomb affixed to the side, it’s possible to drop pallets directly from the rear of any vehicle or a helicopter.